Charl Schwartzel has withdrawn from the South African Open after picking up a stomach virus.
The former Masters champion had been in hospital intermittently for treatment and had to go for rehydration treatment.
The South African Open, which takes place at Johannesburg's Glendower Golf Club from January 7 to 10 is one of the few titles Schwartzel is yet to win in his homeland.
"I am hugely disappointed to be missing out on the SA Open," Schwartzel said in a statement to the media.
"Everybody knows how keen I am to win our national Open and, having come so close the last couple of years and following my good form at Leopard Creek, I was really looking forward to contending at Glendower.
"I look forward to being strong and healthy in time for the Joburg Open the following week."
The US President was among the viewers watching the TaylorMade Driving Relief.
The US President phoned in as McIlroy played in a Sunday fundraiser for coronavirus victims.
Syme donated his prize money to charity.
‘This is the life of a caddie…’
The Northern Irishman is ranked number one in the world.
Players entering the United States will face a 14-day quarantine period, while a strict testing regime will be in place at each tournament.
The experienced duo will be involved at Whistling Straits.
The world number 98 intends to split the 10,000 euros prize money between his own charity and a hospital in his native Rotterdam.
The biennial event between Europe and the United States is scheduled to take place from September 25-27.